000
AXNT20 KNHC 182339
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN JAN 18 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N10W CROSSING THE EQUATOR NEAR 
20W THEN ALONG 1S22W 1S38W INTO NE BRAZIL NEAR 3S44W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM ON EITHER 
SIDE OF A LINE FROM 2S26W TO 5N40W. 

...DISCUSSION...

GULF OF MEXICO...
A DEEP LAYERED TROUGH IS ACROSS THE ERN CONUS AND SUPPORTS A 
COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR TALLAHASSEE 
FLORIDA AND EXTENDS SW INTO THE GULF ALONG 28N90W TO THE MEXICO 
COAST NEAR 24N98W. COASTAL DOPPLER RADAR IMAGERY SHOWS SCATTERED 
SHOWERS WITH EMBEDDED ISOLATED TSTMS ACROSS THE NE GULF AND 
FLORIDA PANHANDLE...WITH SCATTERED SHOWERS EXTENDING WITHIN 90 
NM E OF THE FRONT ACROSS THE CENTRAL GULF WATERS. A WEAK RIDGE 
OF HIGH PRESSURE EXTENDS FROM THE W ATLC THROUGH THE FLORIDA 
STRAITS INTO THE SRN GULF ALONG 24N. ALOFT...NORTHWESTERLY FLOW 
DOMINATES OVER THE GULF WITH MODERATE TO STRONG SUBSIDENCE NOTED 
OVER THE SRN FLORIDA PANHANDLE AHEAD OF THE SURFACE FRONT AND 
ANOTHER SUBSIDENCE AREA BEHIND THE FRONT ACROSS THE NW AND 
N/CENTRAL GULF.

CARIBBEAN SEA...
A SURFACE TROUGH EXTENDS FROM THE W ATLC ACROSS HISPANIOLA TO 
NEAR 12N76W. SCATTERED LOW-LEVEL SHOWERS ARE OBSERVED ACROSS 
HISPANIOLA AND WITHIN 90 NM OF A 18N72W TO 12N78W LINE. AREAS OF 
OVERCAST LOW CLOUDS AND SCATTERED SHOWERS ARE ALSO ALONG THE WRN 
PANAMA AND COSTA RICA COASTS...AND ELSEWHERE OVER INLAND 
HONDURAS...GUATEMALA...SRN BELIZE...INCLUDING ADJACENT COASTAL 
WATERS S OF 18N AND W OF 82W. NORTHERLY WINDS ARE OBSERVED 
ACROSS THE WRN CARIBBEAN W OF 75W...WHILE MODERATE TRADEWINDS 
CONTINUE E OF 75W. ALOFT...AN UPPER LEVEL TROUGH IS OVER THE WRN 
CARIBBEAN W OF 70W AND N OF 14N. AN UPPER LEVEL RIDGE IS OVER 
THE ERN CARIBBEAN WITH AXIS ALONG 62W. STRONG SUBSIDENCE IS OVER 
THE ENTIRE CARIBBEAN BASIN AND CENTRAL AMERICA.

ATLANTIC OCEAN...
BROAD UPPER LEVEL TROUGHING IS ACROSS THE W ATLC N OF 20N AND W 
OF 65W. THIS TROUGHING SUPPORTS A STATIONARY FRONT THAT ENTERS 
THE DISCUSSION AREA NEAR 32N55W AND EXTENDS SW ALONG 27N65W TO 
NORTH OF HISPANIOLA NEAR 21N70W. BROKEN TO OVERCAST LOW CLOUDS 
AND SCATTERED SHOWERS ARE WITHIN 90 NM ON EITHER SIDE OF THE 
FRONT. ELSEWHERE...A 1034 MB SURFACE HIGH PRESSURE IS CENTERED 
NEAR 32N30W AND COVERS THE REMAINDER OF THE E ATLC E OF 55W. 
THIS SURFACE HIGH IS SUPPORTED ALOFT BY A STRONG UPPER HIGH 
CENTERED NEAR 25N33W. MOSTLY BROKEN LOW CLOUDS ARE N OF 10N 
BETWEEN W AFRICA AND 50W.

$$
HUFFMAN